[V8] Engine rebuild options
urq at pacbell.net
Wed Aug 27 19:48:34 PDT 2008
IMO we're not talking about the head design, rather the design of the oil
vapor recovery system that sits in the valley between the heads. Years ago
Scott and I compared notes on this ... What I found in my research of oil
vapor recovery systems was that some manufacturers use brass or steel wool
as a surface onto which the oil could collect ... where it would hopefully
drain into the return galleries as Dr. Oeldrucker intended. What happens on
acceleration is the oil sloshes up to the line where only fumes are intended
to pass. One time I pulled the line at the front of the engine where the
oil recovery line attaches to the intake manifold and saw signs of liquid
oil. If someone wanted proof positive they could block the line at the
intake manifold, feed the vapor recovery line to some sort of container ...
and then go around and have some fun for a little while ... decelerating
down long hills and then punching it at the bottom, or replicating any other
sequence that in the past has caused a smokescreen a battleship captain
would be proud of. I suspect the issue will be resolved ...
My theory as to why a rebuilt motor resolves the problem is that the tighter
rings/valve seals reduce the amount of blow by gasses, which leads to less
oil vapor to build up in the recovery system. I have a pad of brass wool
which I was planning to drop into the recovery system on the PT I have
sitting in the garage (that engine that came from #2).
San José, CA (USA)
> However, I think there's something to Scott's theory about venting the
> at the back. I guess if every acceleration is a hard one, pushing the oil
> inot the venting system could lead to a problem.
if it's really about the head design, I wonder why the ABH is more
affected than the PT (that's at least our experience). And IF it is
nevertheless the head design, what can be done against it?
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